Gelatin coating compositions with n-tallow-beta-iminodipropionic acid



United States Patent 3,506,449 GELATIN COATING COMPOSITIONS WITH N-TAL-LOW-fi-IMINODIPROPIONIC ACID William J. Knox, Rochester, N.Y., assignorto Eastman Kodak Company, Rochester, N.Y., a corporation of New JerseyNo Drawing. Filed Sept. 20, 1962, Ser. No. 225,108

Int. Cl. G03c 1/02; C09d 3/04 U.S. Cl. 96-94 9 Claims ABSTRACT OF THEDISCLOSURE This invention relates to proteinaceous coating compositionsand photographic elements containing the same wherein said coatingcomposition comprises the salt of N-tallow-fl-iminodipropionic acid,

This invention relates to proteinaceous compositions such as of gelatinor casein, containing a coating aid of an alkyl derivative ofiminodiacetic or iminodipropionic acid therein.

In the photographic industry it is often desirable that the proteincoatings, either the photographic emulsion or other coatings, have bothgood surface slickness and good developer wettability,

In the coating of film or paper with a gelatin layer such as of aphotographic emulsion or some other gelatin coating composition, uniformapplication of the composition to the surface to which it is supplied isdesirable especially at good production speeds. When no coating aid isused, defects such as repellencies, pencil line streaks or the likearise. Saponin has been employed, in this connectio; as a coating aidbut this material has been found to vapy markedly from batch to batch inquality and composition. Not only may this adversely affect aphotographic emul v sion containing it but in some instances only littleor no improvement in coating properties may be obtained.

A number of synthetic materials have been suggested as coating aids ingelatin compositions and many of these materials have shown themselvesto be useful in applying a gelatin coating to a surface. Sometimes,however, these coating aids have left something to be desiredparticularly in coating methods in which several coatings are applied toa support simultaneously such as in the manner described in U.S. PatentNo. 2,761,791 of T. A. Russell.

One object of this invention is to provide proteinaceous coatingcompositions which yield blemish-free coatings having good surfaceslickness and developer wettability when those compositions are laiddown as a layer upon a support. Another object of this invention is toprovide gelatin and casein coating compositions which are useful whenapplied over paper or film base support or over a previous gelatincoating residing upon a support. A further object of this invention isto provide proteinaceous coating compositions containing alkali metalsalts or alkyl derivatives of iminodiacetic acid and or iminodipropionicacid in which the alkyl radical is 12-18 carbon atoms. Other objects ofthis invention will appear herein.

It has now been found that salts of alkyl derivatives of iminodiaceticor iminodipropionic acid, the alkyl radical being of 12-18 carbon atoms,are useful as coating aids in proteinaceous coating compositions givinglayers having good surface slickness, good developer wettability, whichcompositions are useful for application either over a support or over aprevious proteinaceous coating, We have found that coatings may beapplied from three compositions which are substantially free of defectssuch as pencil line streaks, mottle and general streakiness such asfrequently characterizes coatings especially in multiple layer hoppercoating operations.

3,506,449 Patented Apr. 14, 1970 The coating aids which I have found tobe useful in proteinaceous compositions are those having the formula:

in which x=l2, R=a 11-17 carbon hydrocarbon radical and M is a cationwhich will contribute to the water solubility of the coating aid and maybe ammonium, sodium or some other alkali metal. Of particular usefulnessare those coating aids such as the alkali metal or ammonium salts ofN-tallow-fl-iminopropionic acid in which tallow has been used to supplythe alkyl radical of the acid which comprises mainly C and Cgroupshexadecyl and octadecyl groups. See Feiser and Feiser,Introduction to Organic Chemistry, 1957, D. C. Heath and Company, page295.

Coating aids of this type may generally be prepared as known in theprior art and as disclosed in Bulletin 15'-A, Deriphats, General MillsChemical Division, 1961, and in U.S. Patents 2,468,012 and 2,816,920.Tallow which can be used in the preparation, for example, may have asthe relative proportions of the acid port on thereof 61% stearoyl(stearic acid), 6% palmitoyl (palmitic acid) and 33% oleyl (oleic acid).It has been found that in general the coating aid should be used in aconcentration between about 0.2 and 2.7 parts per parts of the protein,e.g., gelatin or casein, in the composition.

Although the protein compositions in accordance with this invention areuseful for applying single layers they are especially useful in thelaying down of a plurality of layers in a simultaneous coating operationin a multiple coating technique such as on the order of that describedin U.S. Patent No. 2,761,791 of T. A. Russell. Coating operations ofthis type give coatings substantially free of defects. Instead of amultiple layer operation in which the layers are simultaneously applied,the plurality of layers may be applied in sequence such as by coatingone layer over a previous gelatin or casein layer either by a wet-onwetcoating operation or by a wet-on-dry procedure.

The following examples illustrate coating procedures employingcompositions in accordance with our invention:

EXAMPLE 1 There was applied simultaneously to paper by a multiplecoating technique as described in U.S. Patent No. 2,761,791 agelatin-silver halide photographic emulsion and an aqueous gelatinovercoating layer using as the coating aid in each composition thesodium salt of N- tallow iminodipropionic acid in concentrations from0.07 to 0.5 gram per pound of composition. The resulting layers in eachcase exhibit good developer spreading and slickness values as comparedto compositions in which no coating aid was used. Also the productsexhibited freedom from streakiness and other similar coating defects,The developer wettability is determined by recording the area coveredupon delivering one ml. of developer solution to a fiat section of adried coating and measuring the area in square centimeters which is wetthereby.

EXAMPLE 2 A wet-on-dry application was made of a dyed gelatin coating tofilm base as an antihalation layer. The coating aid used was the sodiumsalt of N-tallow iminodipropionic acid in the proportion of 0.22 gramper pound of gelatin overcoating composition. The resulting coating hada smooth surface and was substantially free of mottle or streakiness.

EXAMPLE 3 Coatings of gelatin-silver halide photographic emulsion havingtherein as the coating aid a mixture of the disodium salts of N-tallowiminodipropionic acid and N- lauroyl carboxymethyl glycine were coatedout onto paper. The ratios of the two coating aid materials were 3:1 and1:3 respectively, the coating aid being present in each case in aconcentration of 0.25 gram per pound of wet emulsion. In each caseproducts were obtained having good surface slickness, good smoothness,good wettability with developer solution and freedom from surfacedefects.

In each of the examples given each pound of composition contains 37grams of gelatin or casein. The coating aid is present in an amountwithin the range of about 1.9 to about 2.7 parts thereof per 100 partsof the gelatin or protein in the coating composition in which it isused.

I claim.

1. A coating solution for coating at least one layer of a photographicelement comprising a proteinaceous composition and containing a wettingagent which comprises an alkali metal or ammonium salt ofN-tallow-fi-iminodipropionic acid.

2. A coating composition according to claim 1 wherein said coatingcomposition comprises a silver halide.

3. A coating composition according to claim 1 wherein said coatingcomposition comprises a silver halide and said proteinaceous compositioncomprises gelatin.

4. A coating solution for coating at least one layer of a photographicelement comprising a proteinaceous composition and containing a wettingagent which comprises disodium salt of N-tallow-fl-iminodipropionicacid.

5. A coating solution according to claim 4 wherein said disodium salt ofN-tallow-fi-iminodipropionic acid is present in an amount ranging fromapproximately 0.2 to 2.7 parts per parts of said proteinaceouscompositron.

6. A coating solution according to claim 4 which comprises a silverhalide composition.

7. A coating solution according to claim 4 wherein said proteinaceouscomposition comprises gelatin.

8. A photographic element comprising a support, at least onelight-sensitive silver halide layer and at least one layer comprising aproteinaceous composition and containing a wetting agent comprising analkali metal or ammonium salt of N-tallow-fl-iminodipropionic acid.

9. A photographic element according to claim 8 wherein saidproteinaceous composition is a gelatin.

References Cited UNITED STATES PATENTS 2,240,471 4/1941 Swan 1l71642,919,197 12/1959 Duin 260404 2,933,406 4/ 1960 Salzberg et al. 1061252,958,605 11/1960 Leiner et a1. 106-125 2,992,109 7/1961 Allen 961 112,994,611 8/1961 Heyna et al. 96111 3,038,804 6/1962 Knox et al. 961113,133,816 5/1964 Ben-Ezra 9694 J. TMVIS BROWN, Primary Examiner US. Cl.X.R.

